Dynamic selection of sequencing rules for a class-based unit-load automated storage and retrieval system

This paper studies dynamic selection of sequencing rules for a class-based unit-load automated storage and retrieval system (AS/RS). A multi-pass and genetic algorithm (MPGA) simulation system is developed and it divides storage and retrieval requests or dual commands into a series of blocks, and then conquers each block to find the most promising combination of sequencing rules. These rules are first come first served (FCFS), shortest total-travel time (STT) and shortest due time (SDT), and they can be chosen dynamically in any decision points in the system. An experiment shows that our approach with dynamic rules is much better than those approaches with any single rule used from the beginning to the end in the whole system. The results of this study provide a better way to control and manage the operation of AS/RS.     

Optimal random storage allocation for an AS/RS in an FMS

A flexible manufacturing system (FMS) comprises, automated machine tools, automated material handling, and an automated storage and retrieval system (AS/RS) as essential components. Optimal performance of each element of this system would improve the productivity and efficiency of the total FMS. In this context, this paper attempts to link the operation of the AS/RS with the production schedule and suggests two different classes of algorithms, namely, heuristics and genetic algorithms to improve the performance of the AS/RS operation by allocating the materials with minimum movement of the shuttle.     

大型周转型自动化仓库的倒库算法

为提高出库效率,优化自动化仓库的货物布局,提出了基于分层序列法思想的自动化仓库倒库优化算法。根据“货物距离出口最近”和“空筐距离出口最远”原则生成仓库货物的最佳布局位置,以单目标序列优化法对倒库作业进行优化。该算法已应用于某机场大型自动化周转仓库监控管理系统,提高了出入库效率。     

An innovative automated storage and retrieval system for B2C e-commerce logistics

Flexible and timely warehousing activities provide a strong foundation for logistic systems. However, increasing B2C e-commerce with a variety of small internet orders may have a tremendous impact on warehousing. Automated storage/retrieval systems (AS/RSs) are a valid alternative for warehousing. Typical AS/RSs design and control problems in a static environment and cannot effectively manage parcel, small, and irregular items. This study proposes a new AS/RS that is more efficient and flexible for handling B2C e-commerce logistics. An auto-access multilevel conveying device (IMCD) with three-dimensional movement is integrated into the AS/RS. The ant colony system algorithm locates near-optimal routes for the IMCD. Typical travel distance/time measures evaluate the performance of an S/R device running on a warehouse floor. However, the performance index in this study looks at the IMCD’s travel time with three-dimensional movement in completing a batch order. To validate the new AS/RS, two simulation experiments were conducted to examine the effects of three-dimensional velocity and rack shape. Finally, this study compares a typical S/R system with the new AS/RS and makes recommendations for practical applications and further research.     

基于MCGS组态软件的自动化立体仓库控制系统的开发

通过设计一套自动化立体仓库,达到解决城市用地紧张,降低劳动强度,提高工作效率等的目的。它的控制系统是以西门子PLC作为控制系统的核心,利用MCGS组态软件设计出自动化立体仓库上位机监控界面,MCGS组态软件通过设备驱动程序从现场硬件设备获取实时数据并处理,通过指示灯显示货物是否完成到位,并由操作人员按照要求将控制指令数据送给现场硬件设备,以控制立体仓库码垛机械手的各种动作,实现对货物的自动化存取。     

烟丝原料立体仓库堆垛机出入库作业优化研究

为了提高烟丝原料立体仓库堆垛机的作业效率,解决多台堆垛机作业不均衡问题,提出了以各堆垛机作业时间总和最小与作业时间均衡为目标的出入库作业优化模型.在该模型中,用出入库优化作业的规则替代原有作业规则.为了寻求最佳的出入库货位序列,该模型通过构建货位坐标系,采用堆垛机在全速和减速运行状态下联合作业和单作业两种模式的作业时间计算方法,提高了出入库的作业效率.在相同参数下,对一个具体烟丝立体仓库实例进行了作业优化前后的比较.结果表明,通过采用优化作业方法,作业效率每小时可以提高82个烟包,各堆垛机的作业不均衡性大为减小.     

Evaluation and dynamic allocation of AS/RS control rules: A simulation study

The goal of this research is to investigate the performance of an automated storage and retrieval system (AS/RS) which is operated using different control rules. Two phases of study are conducted. Phase 1 evaluates the efficiency of different rules for stacker control, storage-location assignment and job sequencing. Phase 2 studies the impact of these rules on the performance of the AS/RS using a multipass simulation approach. In this paper, the methodology of investigation is discussed, the results are presented and analysed, and suggestions for future study are made.     

Dual commands dispatching of a class-based unit-load automated storage and retrieval system using multi-pass simulation with generic algorithm

A simulation system with the approach of multi-pass and genetic algorithm (MPGA) is developed for dispatching dual commands by a stacker machine in a unit-load/class-based automated storage and retrieval system (AS/RS). Three single-rules, FCFS/STT, SDT/STT, and STT_bk, are run individually by a single-pass simulation and served as the benchmarks to compare with the performances of three kinds of the MPGA approach. All experiments, singles and MPGA, start with the same initial system states and run with the same input data streams. Due to a larger solution space for the optimal search and an iterative searching method, the MPGA approach greatly improves the performances of our AS/RS model, compared with traditional approaches.     

自动化立体仓库中载人联机可视化拣选方案及其性能分析

提出了一种新颖的利用网络技术和触摸屏进行载人巷道堆垛机上的可视化拣选操作方案，配合存储货位分配策略和执行批量拣选作业的优化顺序方式，可以提高自动化立体仓库中载人拣选作业方式的工作效率，增加拣选操作的吞吐率，在概述了这种新方案的实现框架之后，给出了这种方案的性能模型，并对具有动态作业插入时的系统性能进行了分析。     

自动化立体仓库控制系统设计与实现

本文介绍的自动化立体仓库控制系统采用由一台工业控制计算机和3台PLC怕集散型控制网络,实现了集监控、调度、诊断、货位分配、堆垛机运行参数给定等功能于一体的自动化立体仓库控制系统和堆垛机制系统以及立体仓库数据库管理系统。工业现场运行证明了这种设计、控制思路的先进性。     

自动化立体仓库货位优化研究

分析了自动化立体仓库货位优化的问题,建立了自动化立体仓库货位优化的数学模型,采用遗传算法研究了货位优化的方法,通过实例仿真分析,优化后显著提高了货架的稳定性,并且提高了货物的存取效率。     

Simultaneous optimisation of control factors in automated storage and retrieval systems and FMS using stochastic coloured Petri nets and the Taguchi method

Automated storage and retrieval systems (AS/RS) are playing an important role in modern manufacturing systems such as flexible manufacturing systems (FMS). The integration of AS/RS systems and FMS is very complex owing to the complexity of the individual elements. Stochastic coloured petri nets (SCPN) can be used to model, simulate and analyse such a system efficiently and realistically. In this paper, SCPN based simulation, aided by the Taguchi method of design of experiments, has been used for analysing the influence of important factors on makespan, unproductive travel time, and the mean flow time, and is supported by an example.     

基于FMS的自动化立体仓库监控系统开发与应用术

为了实现对基于柔性制造系统（FMS）的自动化立体仓库（AS／RS）的监控与管理,以浙江机电职业技术学院示范院校建设FMS项目为背景,根据具体实验教学的要求,进行了自动化立体仓库集成监控系统设计,实现了一套功能完备、规范化、工程化的集成监控软件。研究结果表明,该系统的运行效果令人满意。     

基于两阶段狼群算法的自动化立体仓库作业集成优化

为提高单载具自动化立体仓库动态工况下的进出库效率,针对自动化立体仓库作业集成优化问题建立了仿真优化模型。模型根据货物重质、出入库频率划分货架区域,以指令内最小化单载具堆垛机运行时间为研究目标,设计了一种两阶段狼群算法对其进行优化。该算法使用狼群算法对货位分配和作业调度进行集成优化,求解过程体现出两优化问题之间的关联和反馈。实验结果表明,在不同的订单规模下,相比其他优化方式,两阶段狼群算法能得到满意解,并有效缩短自动化立体仓库的作业时间。     

自动化立体仓库系统在飞机钣金模具管理中的应用

通过设计与规划自动化立体仓库管理系统,提出了以满足工段生产需求为目标的物流配送思想,以此思想为导向,优化模具管理流程,理顺内部客户关系,实现了飞机钣金零件模具的高效、准时配送。在飞机钣金模具管理中,与传统的模具仓库管理模式相比,自动化立体仓库系统节省了场地面积,降低了人工成本,提高了零件生产效率。     

Storage assignment optimization in a multi-tier shuttle warehousing system

The current mathematical models for the storage assignment problem are generally established based on the traveling salesman problem(TSP), which has been widely applied in the conventional automated storage and retrieval system(AS/RS). However, the previous mathematical models in conventional AS/RS do not match multi-tier shuttle warehousing systems(MSWS) because the characteristics of parallel retrieval in multiple tiers and progressive vertical movement destroy the foundation of TSP. In this study, a two-stage open queuing network model in which shuttles and a lift are regarded as servers at different stages is proposed to analyze system performance in the terms of shuttle waiting period (SWP) and lift idle period (LIP) during transaction cycle time. A mean arrival time difference matrix for pairwise stock keeping units(SKUs) is presented to determine the mean waiting time and queue length to optimize the storage assignment problem on the basis of SKU correlation. The decomposition method is applied to analyze the interactions among outbound task time, SWP, and LIP. The ant colony clustering algorithm is designed to determine storage partitions using clustering items. In addition, goods are assigned for storage according to the rearranging permutation and the combination of storage partitions in a 2D plane. This combination is derived based on the analysis results of the queuing network model and on three basic principles. The storage assignment method and its entire optimization algorithm method as applied in a MSWS are verified through a practical engineering project conducted in the tobacco industry. The applying results show that the total SWP and LIP can be reduced effectively to improve the utilization rates of all devices and to increase the throughput of the distribution center.     

Travel-time models for flow-rack automated storage and retrieval systems

In this paper, closed-form travel-time expressions for flow-rack automated storage and retrieval systems are developed. The expressions, which are based on a continuous approach, are compared for accuracy, via simulation, with exact models which are based on a discrete approach. There is no significant difference between the results obtained from the continuous-approach-based closed-form expressions and the ones from the discrete-approach-based exact solutions. The closed-form expressions are easy to calculate due to their simplistic forms, even without a computer, while the exact solutions are extremely complex. On the basis of computation time, the proposed closed-form expressions are extremely practical when compared with the discrete-approach-based expressions, which require extensive computation time. The closed-form travel-time expressions developed in this study can be used to (1) establish performance standards for existing AS/RS, (2) evaluate throughput performance for flow-rack AS/RS alternative design configurations, and (3) compare different storage techniques for improved system performance. Due to their simplistic, yet accurate, definitions, the closed-form expressions, as well as the results of this study, are applicable to industry.     

面向仓储物流的建模及控制系统设计方法

为提高现代企业仓储物流的设计质量和效率,提出了一种基于资源颜色时序信号的扩展Petri网建模及控制系统设计方法.该方法首先采用资源颜色时序信号的扩展Petri网建立了仓储系统的动态模型,清晰地描述了各种物流活动的顺序、并发,冲突等关系,并结合关联矩阵,阐述了判断死锁和陷阱的方法.该方法建立的模型可根据Petri网运算规则进行保性化简,便于仿真分析和验证,且可直接用于系统可编程逻辑控制器的控制程序设计.最后,以仓储物流控制系统为例,阐述了系统建模及控制设计过程.     

自动化立体仓库系统在飞机钣金模具管理中的应用

通过设计与规划自动化立体仓库管理系统,提出了以满足工段生产需求为目标的物流配送思想,以此思想为导向,优化模具管理流程,理顺内部客户关系,实现了飞机钣金零件模具的高效、准时配送。在飞机钣金模具管理中,与传统的模具仓库管理模式相比,自动化立体仓库系统节省了场地面积,降低了人工成本,提高了零件生产效率。     

基于PLC的自动化立体仓库控制系统

结合机电一体化技术,完成自动化立体仓库中机械手、堆垛机PLC控制系统设计,实现货物的运输与分配、堆垛机定位控制、出入库控制等功能。该系统具有操作简便,自动化程度高,运行速度快、可靠性高等特点。